From 53f824520b6d84ca5b4a8fd71addc91dbf64357e Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Thu, 3 Sep 2009 14:31:44 -0700 Subject: x86/i386: Put aligned stack-canary in percpu shared_aligned section Pack aligned things together into a special section to minimize padding holes. Suggested-by: Eric Dumazet Signed-off-by: Jeremy Fitzhardinge Cc: Tejun Heo LKML-Reference: <4AA035C0.9070202@goop.org> [ queued up in tip:x86/asm because it depends on this commit: x86/i386: Make sure stack-protector segment base is cache aligned ] Signed-off-by: Ingo Molnar --- arch/x86/include/asm/processor.h | 2 +- arch/x86/kernel/cpu/common.c | 2 +- include/asm-generic/percpu.h | 3 +++ include/linux/percpu-defs.h | 8 ++++++++ 4 files changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index e597ecc8753c..ac7e79654f3a 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -413,7 +413,7 @@ struct stack_canary { char __pad[20]; /* canary at %gs:20 */ unsigned long canary; }; -DECLARE_PER_CPU(struct stack_canary, stack_canary) ____cacheline_aligned; +DECLARE_PER_CPU_ALIGNED(struct stack_canary, stack_canary); #endif #endif /* X86_64 */ diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 7d84bc4c1188..f23e236391a3 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1043,7 +1043,7 @@ DEFINE_PER_CPU(struct orig_ist, orig_ist); #else /* CONFIG_X86_64 */ #ifdef CONFIG_CC_STACKPROTECTOR -DEFINE_PER_CPU(struct stack_canary, stack_canary) ____cacheline_aligned; +DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary); #endif /* Make sure %fs and %gs are initialized properly in idle threads */ diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h index aa00800adacc..90079c373f1c 100644 --- a/include/asm-generic/percpu.h +++ b/include/asm-generic/percpu.h @@ -81,14 +81,17 @@ extern void setup_per_cpu_areas(void); #ifdef MODULE #define PER_CPU_SHARED_ALIGNED_SECTION "" +#define PER_CPU_ALIGNED_SECTION "" #else #define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned" +#define PER_CPU_ALIGNED_SECTION ".shared_aligned" #endif #define PER_CPU_FIRST_SECTION ".first" #else #define PER_CPU_SHARED_ALIGNED_SECTION "" +#define PER_CPU_ALIGNED_SECTION ".shared_aligned" #define PER_CPU_FIRST_SECTION "" #endif diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index 68438e18fff4..3058cf9dd3d4 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -66,6 +66,14 @@ DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \ ____cacheline_aligned_in_smp +#define DECLARE_PER_CPU_ALIGNED(type, name) \ + DECLARE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \ + ____cacheline_aligned + +#define DEFINE_PER_CPU_ALIGNED(type, name) \ + DEFINE_PER_CPU_SECTION(type, name, PER_CPU_ALIGNED_SECTION) \ + ____cacheline_aligned + /* * Declaration/definition used for per-CPU variables that must be page aligned. */ -- cgit v1.2.3-59-g8ed1b